package com.chenjt.juc.ten_ThreadLocal;


import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

class MyData{
    ThreadLocal<Integer> threadLocalField = ThreadLocal.withInitial(()->0);
    public void add(){
        threadLocalField.set(1+threadLocalField.get());
    }

}


/**
 * 注释：
 * 【强制】必须回收自定义的ThreadLocal变量，尤其在线程池场景下，线程经常会被复用，
 * 如果不清理自定义的 ThreadLocal 变量，可能会影响后续业务逻辑和造成内存泄露等问题。
 * 尽量在代码中使用try-finally块进行回收
 *
 * @author chenjt
 * @date 2024/7/15 11:00
 */
public class ThreadLocalDemo2 {

    public static void main(String[] args) {
        MyData myData = new MyData();

        ExecutorService threadPool = Executors.newFixedThreadPool(3);

        try {
            for(int i = 0;i<10;i++){
                threadPool.submit(()->{
                    try {
                        Integer beforeInt = myData.threadLocalField.get();
                        myData.add();
                        Integer afterInt = myData.threadLocalField.get();
                        System.out.println(Thread.currentThread().getName()+"\t"+"beforeInt:"+beforeInt+"\t afterInt:"+afterInt);
                    } finally {
                        myData.threadLocalField.remove();
                    }
                });
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            threadPool.shutdown();
        }

    }

}
